Process of fractioning browiin from chlorin



UNITED STATES Patented February 16, 1904.

PATENT OFFICE.

HERBERT H. DOW, OF MIDLAND, MICHIGAN, ASSIGNOR TO THE DOW CHEMICAL COMPANY, OF MIDLAND, MICHIGAN, A CORPORATION or MICHIGAN.

PROCESS OF FRACTIONING BROMIN FROM OHLORIN.

SPECIFICATION forming part of Letters Patent No. 752,331, dated February 16,

Application filed May 21,1903. Serial No.-158,0'77. (N0 specimens.)

To all whom it may concern.-

Be it known that I, HERBERTH. Dow, a citizen of the United States, and a resident of Midland, county of Midland, and State of Michigan, have invented a new and useful Improvement in Processes of Fractioning Bromin Apart from Ohlorin, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so

as to distinguish it fromother inventions.

My invention consists of an improved process for fractioning bromin apart from chlorin,

and thus obtaining a mixture of bromiri and chlorin in which the proportion of bromin to chlorin may be any that is desired up to a practical limit, the production of a mixture in which the amount of chlorin shall be small in comparison with the amount of bromin being especially sought. Said process consists of a series of stepshereinafter fully described.

The annexed drawing and the following description set forth in detail one'mode of carrying out the invention, such disclosed means constituting but one of various ways in which the principle of the invention may be used.

In said annexed drawing is represented a diagrammatic view of a form of apparatus used in my improved process.

My improved process is a radical departure in the methods of fractioning apart bromin and chlorin, which are obtainedby'the oxidation of natural brine's, in that heretofore this separation hasbeen accomplished by chemical processes and depended upon the fact that chlorin will liberate bromin from bromide, while-in this process the method is purely mechanical and depends upon the fact that the bromin in a brine solution is more volatile than the chlorin formed in the solution at the same time. I have found that when a natural brine is oxidized sufficiently to set free practically all the contained bromin and air is blown through the heroin thus set free the first portions of air escaping from the bromin solution will carry the p est bromin and later portions of air will carry a Very impure bromin, the impurity both.

cases being chlorin or a volatile compound of chlorin or a combination of the two, some or all of which are produced in quite -a large quantity when the brine is oxidized to its complete bromin content.

Although the method of fractioning bromin apart from chlorin is a radical departure from the methods heretofore used and especially from that described and claimed in my United States Letters Patent No. 714,160, the apparatus used in this process is nearly identical with that used in said Letters Patent, ,difler ingonly in these respects: Auxiliary oxidizer M and its connections, the connection through the blower F between the absorption-towers L and the blow-out towers O, which are shown and described in the view accompanying the patented process, are omitted in this improvement, There is an air-inlet 0 provided for the blow-out tower O in this process that is not provided in the patented process. Also in this process the connection 0 leads from the blow-out towers C to the blow-out towers N insteadrof from the towers O to the auxiliary oxidizer M. The rest of the apparatus both in the main and auxiliary systems performs the same functions in this process-as those describe neither them nor their functions disclosed in the patent, and I shall therefore more in detail, the lettering being identical in c both.

My improved process is carried on as follows: Raw brine from the reservoir R is first vallowed to pass through the absorber Q, where it takes up more or less bromin and; chlorin and passes on to the reservoir A through the connection a. From here it passes through duct 5 to the oxidizer B, where by any of the means explained in my reissued Letters Pat-- ent No. 11,232 it is oxidized, the oxidation being carried to a point where substantially all the bromin content is set free, more or less chlorin incidentally and of necessity being 'simultaneously set free. From the oxidizer the brine carrying all the dissolved bromin in the free state passes through duct 0 to the blowout towers 0. Here a limited amount of air 'is allowed to enter through the inlet 0, and a into the purifiers E through the pipe G, thence through the pipe H, purifiers J, in which a strong bromid solution (provided from a suitable source, such as the receptacle X) is caused to circulate where the last trace of chlorin is removed by the substitution of such chlorin for the bromin in the bromid solution, thence through pipe K, and to the absorption-tower L, which may contain any suitable material, such as sodium carbonate, (the latter being provided from a suitable source of supply, such as the receptacle Y,) which will combine with the bromin exactly as described in Letters Patent No. 714,160.

As has been mentioned above, the bromin.

in a brine solution is more volatile than the chlorin in the solution formed at the saw. 3 time, and by this blowing of the brine with a limited amount of air a mixture'of bromin and chlorin is obtained in which the proportion of bromin to chlorin is much higher than the average proportion of the solution and a far purer bromin product obtained than when a large amount of air is used or when limited amounts of air are used successively. The

proportion of bromin carried away to the air used also increases with the decrease in the amount of air used. The brine in the towers 0 still contains a large amount of free halogens, and from it considerable quantities of a less pure bromin may be obtained. The brine is hence conducted through the pipe 0 to the blow-out towers N, where it is brought into contact with a large amount of air and all the dissolved free halogens blown out, whence they are carried through the duct O to the absorption-towers Q and are taken up by and serve to oxidize the fresh brine coming down from the reservoir R into the towers Qthrough duct 9'. During the passage of the different solutions through the various parts of the appara tus pumps 12,, g, ',.Z, and 0 at the bases of the systems of towers N, Q, E, J, L, and C, respectively, serve to convey the various solutions contained or flowing through said systems of towers successively to the one, two, three, or any number of towers comprising each of the respective systems. I shall call a series of blow-out towers, such as C and N, hereinafter an air system, meaning there by a tower or plurality of towers connccted together for blowing out by means of air a part of the bromin.

As the exact control of the amount of oxidation that takes place is very important in order to get a maximum yield of bromin of the greatest purity consistent with ahigh extraction, it has become very important that this part of the process should be simplified. It is for this reason that in the improved process herewith described I have dispensed with one of the two oxidizers used in my process, as described in Letters Patent No. 714,160. The

It will be noted that by controlling the amount of air allowed to enter the air system C bromin of any desired purity up to the practical limit oj purity may be obtained and that the proportion of bromin to chlorin in the mixture thus blown out may be as l. vrge or small as desired, and, furthermore, b1 oiuiu may be recovered in any desirable quantity in the said air system C, the remainder, an amount as great as is desired, being allowed to be carried by the brine to the second air system N.

I claim I 1. The steps in the process of fractioning bromin apart from chlorin which consist, in oxidizing bromid-containing brine to excess of its bromin content before removing any of the bromin, obtaining substantially pure bromin by passing through the oxidized brine a limited amount of air, and then recovering the bromin from. the bromin-laden air in a suitable absorbent.

2. The steps in the process of fractioning bromin apart from chlorin which consist, in oxidizing bromid-containing brine to excs-s of its bromin content before removing any of the bromin, and then obtaining bromin and chlorin in the form of gaseous mixtures of varying proportions by passing through the oxidized brine, first, a limited amount of air, and, then, a large amount of air.

3. The steps in the process of fractioning brominapart from chlorin which consist, in oxidizing bromid-containing brine to excess of its bromin content before removing any of the bromin, and then obtaining bromin of a graduated degree of purity, by passing through the oxidized brine a limited amount of air, thereby carrying off the bromin most pure, taking up this pure bromin in a suitable absorbent, passing a large amount of air through the brine, and then taking up the impure bromin, thus blown out, in a natural brine.

4. The steps in the process of fractioning bromin apart from chlorin which consist, in oxidizing bromid-containing brine to excess of its bromin content before removing any of the bromin, and then obtaining bromin of a graduated degree of purity, by passing through the oxidized brine a limited amount of air, thereby carrying off the bromin most pure, taking up this pure bromin in sodium carbonate, passing a large amount of air through taking up this pure bromin in a suitable abthe brine, and then taking up the impure brosorbent, passinga large amount of air through min, thus blown out, in a natural brine. the brine without further oxidation and then 5. The steps in the process of fractioning taking up the impure bromin, thus blown out, 5

5 bromin apart from ehlorin which consist, in in a natural brine.

o fridizing bromid-eontgirfling brine to excess-? Signed by me this 19th day of May, 1903.

0 its romin content e ore removing anyo the bromin, and then obtaining bromin of a HERBERT graduated degree of purity, by passing through Attest: 10 the oxidized brine a limited amount of air, D. 'T. DAVIES,

thereby carrying off the bromin most pure, G. W. SAYWELL. 

